I have been loosing power a little at a time until I can barely keep 60MPH going up a hill without a load. I have replaced the spark plugs, air filter. There are no engine codes being shown. The car acts fine at idle, and runs well, just no power in high gear going up a hill. I have run mobile 1 full synthetic oil with regular changes since 50K on the car. Done all the maintenance. Was thinking maybe timing chain skipped a tooth, or maybe the VVT valves... Looking for any possible answers. Without any engine codes it hard to track down. I do hear a winning noise when I push down about 3/4 on the gas, which might indicate something. Any Ideas?

 

Welcome to the site.

Just an internet guess here. Have the exhaust checked. Particularly the catalytic converter for possible clogging or obstruction.

Have you pulled the codes ? Some codes can be stored in the computer and not always trigger the Check Engine light.

 

My internet guesses are vacuum leak or flex pipe.

 

Can you record and share the sound you hear at 3/4 throttle? Also, perhaps a floorboard video of sounds while in motion to see if there is anything?

I had to do that to determine that I had a bad HUB assembly for mine, but it may help identify yours.

 

I will put the code reader on and seee if any codes are present ... soon to follow

 

I sprayed carb cleaner around (no rpm variation) I am guessing no vacuum leaks ... but will keep looking

 

Will put a pressure gauge on the exhause before the CC and see what the pressure is at idle and 3500 rpm. I ran my had all around the exhaust and didn't feel or hear any leaks ...

 

The noise is also present when in netural, when I rev it up to 3 or 4 grand.

 

Seems like the crack flex pipe issue I had last year, same symptoms but I thought the same I can't feel anything, then 700 miles south from home the pipe cracked open at the flex joint, I continued my vacation a little harder on gas milage and replaced the whole flex joint and cat con pipe for $168.00 from good old EBay.

 

Hey mike421956,

If you'd like any assistance in reaching out to your local Chevrolet dealership regarding your loss of power, I'd be happy to do that for you. Please PM us with your contact info, VIN, and preferred dealership and I would be happy to bring your issue to their attention.

Feel free to send any other questions our way, too. We're here to help!

Geoff G.
Chevrolet Customer Care